06/16/2026
Chronic/Recurrent Colic in the Horse
Brian S. Burks, DVM
Diplomate of the American Board of Veterinary Practitioners®
394 Fox Road
Apollo, PA 15613
(724) 727-3481
www.foxrunequine.com
Colic is a symptom and is abdominal pain, generally of the gastrointestinal tract. Chronic colic is that which has been present for at least three days, whether continuously or intermittently. It may also originate from the liver, spleen, uterus, kidney, and peritoneum. Recurrent colic refers to episodes of abdominal pain separated by days or weeks where the horse appears to be normal.
Pain from the GIT is the result of distention, mesenteric tension, inflammation, or spasm from hypermotility. Chronic colic does not include strangulating obstructive disorders such as small intestinal volvulus.
Affected horses may have a history of dietary or exercise change, lack of access to water, deworming, weight loss, infection, or abdominal surgery. A change in attitude (depression/lethargy), appetite, or f***l output may be noted.
Clinical signs of chronic or recurrent colic are typically mild to moderate. These include an extended neck, flehmen response, bruxism, pawing the ground, flank watching, kicking the abdomen, pinned ears, frequent recumbency, and rolling.
Vital signs are often normal or only mildly elevated. Abdominal distention may or may not be present. Mucous membrane color may change slightly, and the capillary refill time may increase slightly. Heart and respiratory rates may increase moderately. Intestinal borborygmi may be decreased, normal, or increased. F***l output may be normal, reduced, absent, or diarrhea.
The most common cause of chronic colic is large colon impaction, but there are many other causes, including peritonitis, enteritis/colitis, colon displacement, gastric or colonic ulceration, and intussusception. Recurrent abdominal pain is most often caused by intestinal motility disorders, often due to inflammation (inflammatory bowel disease) from a variety of causes including parasitism, sand, and immune system disorders. There may be intestinal obstruction from enteroliths or neoplasia, or intra-abdominal masses such as abscesses or neoplasms.
Diagnosis, like most diseases is based upon signalment, history, and clinical signs. Previous surgery, diet, environment, NSAIDs, tapeworms and other parasites, no water access, severe dental disease, sudden change in exercise (usually less movement), deworming, and pregnancy are all risk factors.
Blood work is common to the diagnostic work up of any horse with colic. This can help identify non-intestinal causes of pain, infection, hypoproteinemia, anemia, leukocytosis, electrolyte abnormalities, and metabolic derangements.
Abdominocentesis is useful to evaluate peritoneal fluid for inflammation or neoplasia. F***l analysis is useful to look for sand and parasitism. F***l bacteriology is used to identify infectious causes of abdominal pain. Re**al palpation is used to identify distended or ruptured viscus. Ultrasonography evaluates abdominal fluids, intestinal wall thickness, intestinal diameter, motility, intussusception, abscess, and adhesions. Radiographs are occasionally useful to evaluate for enteroliths or sand accumulation but are of limited value in all but miniature horses and foals. Gastroduodenal endoscopy identifies ulcers, strictures, parasites (bots, ascarids) and neoplasia. I take biopsies of the stomach, duodenum, and re**um to look for inflammatory bowel disease of various etiologies.
Treatment depends on the source of the problem. It may be supportive or curative, medical or surgical. Most horses require some analgesic or anti-inflammatory medication to control abdominal pain. Laxatives are given per nasogastric tube for impactions. The best laxative is water with electrolytes. Magnesium sulfate is useful to pull fluid into the colon. Mineral oil, in my opinion, is archaic. It is not a good laxative and can interfere with horses that end up requiring surgery (mineral oil in the peritoneal cavity). Mineral oil should never be given by oral syringe as it does not elicit a good swallow reflex and can easily be aspirated into the lungs, where it causes necrosis and death.
Horses with parasitism require anthelmintics based on the type of parasite present. The most common parasites are cyathostomins, tapeworms, and blot fly larvae. Ascarids (round worms) are common in foals and yearlings. There are special deworming protocols for horses with inflammatory bowel disease caused by parasites.
Inflammatory bowel disease often requires treatment with steroids for several weeks to months. IBD can progress to untreatable with severe weight loss and diarrhea.
Horses with gastric ulceration are typically treated with GastroGard for at least one month; however, ulcer location and severity should be noted via endoscopy to make sure that the correct medication is used. Since NSAIDs are a common cause of glandular gastric ulcers and colonic ulcers, these horses should not be given phenylbutazone or fluinixin meglumine. Some horses will develop ulcers even at normal doses of these medications, but all horses are at risk when higher than recommended doses are used (which also give no additional effect). Colonic ulcers are difficult to treat, and low-residue diets are recommended.
Dehydrated horses require fluids enterally, intravenously, or both. Severe dehydration requires intravenous fluid therapy. Oral fluid is contraindicated in some situations. Intravenous antibiotic therapy may be indicated for infectious diseases such as peritonitis.
Some horses with chronic/recurrent colic require exploratory laparotomy to find the lesion or to treat an impaction of the cecum or colon that is not resolving medically.
Fox Run Equine Center
www.foxrunequine.com
(724) 727-3481
